The Latest: Forecasters: Hurricane Michael gaining strength

Data from hurricane hunter aircraft flying through Hurricane Michael show the storm is still strengthening over the Gulf of Mexico.

At 11 a.m. EDT, the National Hurricane Center said Michael had top sustained winds of 110 mph (175 kph). That's just below the threshold for a "major" hurricane, and forecasters say they still expect Michael to get stronger.

Michael was moving north at 12 mph (19 kph). The hurricane is expected to make landfall in Florida'sPanhandle or Big Bend on Wednesday before crossing Georgia and the Carolinas as a weaker storm.

The storm's effects will be felt far from the eye of the hurricane. Forecasters said Michael's storm winds stretched 370 miles (595 kilometers) across, with hurricane-strength winds extending up to 35 miles (55 kilometers) from the center.

10:50 a.m.

Forecasters say Tropical Storm Nadine has formed over the open Atlantic.

The storm is about 480 miles (770 kilometers) off the Cabo Verde Islands and is posing no threat to land.

The National Hurricane Center in Miami said Nadine had top sustained winds of 40 mph (65 kph).

Meanwhile, Tropical Storm Leslie is meandering over the central Atlantic with top sustained winds of 65 mph (100 kph).

10:30 a.m.

The death toll from Hurricane Florence has increased to a total of 51 as another hurricane now bears down on the southeastern United States.

North Carolina'sOffice of the Chief Medical Examiner ruled that the death of a 68-year-old man in Onslow County on Sept. 20 was a storm-related fatality. The office says he died of a "natural disease" made worse by storm cleanup. His name wasn't immediately released.

That raises North Carolina's toll to 40. Another 11 deaths in South Carolina and Virginia have been blamed on Florence.

The Carolinas are bracing for more wind and rain on Wednesday from Hurricane Michael, which is churning toward Florida'sGulf Coast and is expected to drive inland after landfall.

9:50 a.m.

Emergency officials across the Carolinas are warning residents to monitor Hurricane Michael, which is expected to move through the region after coming ashore along Florida'sGulf Coast. They're expecting heavy rain, tropical storm-force winds and tornados beginning Wednesday.

South Carolina's emergency management director Kim Stenson said the severity will depend on the storm's intensity after it blows over Florida, Alabama and Georgia. Residents of the Carolinas are still dealing with the aftermath of Hurricane Florence, which struck the Atlantic coastline last month.

A tropical storm watch is in effect for the southern two-thirds of the South Carolina coast, from Florida up to the South Santee River.

9:40 a.m.

Forecasters say Georgia could see evacuations and rescues as Hurricane Michael brings torrents of rain across the state.

The National Weather Service said Tuesday that central Georgia could see wind gusts as high as 60 mph (97 kph), with the strongest winds south of Columbus and Macon. And rainfall in Georgia could range from 3-5 inches (8-13 centimeters), with locally higher amounts of up to 7 inches (18 centimeters).

The storm has strengthened into a Category 2 hurricane with top wind speeds of 100 mph (155 kph) and is expected to grow stronger before hitting the Florida coast Wednesday. Then it's expected to move over Alabama and Georgia Wednesday and the Carolinas and Virginia on Thursday.

8:50 a.m.

Florida Gov. Rick Scott is warning that Hurricane Michael is a "massive storm" that could bring "total devastation" to parts of the state.

Scott activated 2,000 members of the Florida National Guard on Tuesday to deal with the fast-moving storm expected to hit the state within the next 24 hours.

The governor said he is very concerned about a potentially "historic" storm surge when Michael makes landfall somewhere in the Panhandle.

The threat has already prompted mandatory evacuation orders in counties across northwest Florida. Scott said some places could experience a storm surge of between eight and 12 feet of water as Michael blows ashore.

8 a.m.

Hurricane Michael has strengthened into a Category 2 storm with top wind speeds of 100 mph (155 kph) as it continues its path toward the Florida Panhandle.

As of 8 a.m. Tuesday, the storm was moving north-northwestward over the southern Gulf of Mexico at about 12 mph (19 kph).

The National Hurricane Center in Miami says the hurricane was 395 miles (635 kilometers) south of Panama City, Florida, and 365 miles (590 kilometers) south of Apalachicola, Florida.

Mandatory evacuations are in effect along much of Florida's northern Gulf Coast, stretching from the Panhandle into the area known as the Big Bend.

Michael is forecast to hit the Florida coast Wednesday before moving over Alabama, Georgia and the Carolinas Wednesday night and Thursday.

7 a.m.

Mandatory evacuations are under way in Panama City Beach and across other low-lying parts of the Florida Panhandle as Hurricane Michael approaches.

The evacuation orders went into effect Tuesday morning for some 120,000 people near the beach and other areas of Bay County. During an emergency meeting of the Bay County Commission on Monday night, Sheriff Tommy Ford said people will "not be dragged out of their homes," but reminded those who stay that first responders may not be able to reach them once the storm hits.

Ford says "people need to start leaving now," adding that the roads are going to get "more and more congested as time goes on."

Commissioner Bill Dozier also reminded anyone staying behind to stock up on supplies and "don't expect the government to help take care of you. You need to take care of yourselves."

The National Hurricane Center in Miami said Hurricane Michael was centered about 420 miles (675 kilometers) south of Panama City at 5 a.m. Tuesday.

5:00 a.m.

Hurricane Michael continues to gain strength as it moves through the southern Gulf of Mexico.

By 5 a.m. Tuesday, Michael's top sustained winds had risen some to 90 mph (144 kph) as it headed north at 12 mph (19 kph).

The Category 1 storm was centered about 390 miles (627 kilometers) south of Apalachicola and 420 miles (675 kilometers) south of Panama City, Florida. Hurricane-force winds extended outward up to 35 miles (56 kilometers) from the core and tropical-storm-force winds out 175 miles (280 kilometers). Hurricane-force winds extended outward up to 40 miles (64 kilometers) from the core and tropical-storm-force winds out 195 miles (313.81 kilometers).

Forecasters say the center of Michael will continue to move over the southern Gulf of Mexico Tuesday morning. The storm will then move across the eastern Gulf of Mexico later Tuesday into the night.

The center is then expected to move inland over the Florida Panhandle or Florida Big Bend area on Wednesday, and then move northeastward across the southeastern United States Wednesday night and Thursday.

12:00 a.m.

Michael has gained new strength over warm tropical waters and is forecast to quickly intensify into a major hurricane before a midweek landfall on Florida'sGulf Coast

In the Florida Panhandle and surrounding areas, people are frantically boarding up homes, filling sandbags and planning for evacuation routes away from the storm's projected strike zone.

A hurricane hunter plane that bounced into the swirling eye of Michael off the western tip of Cuba late Monday found wind speeds were rising even as forecasters warned the storm could reach major hurricane status with winds topping 111 mph (179 kph) by Tuesday night.

Florida Gov. Rick Scott calls it a "monstrous hurricane" and is warning of a potentially devastating strike sometime Wednesday.